Western University physics professor Paul Wiegert is working with PhD student Cole Gregg on an astronomical discovery. Alpha Centauri is the nearest star system to ours, and it is currently sending space junk our way.
Space junk is anything smaller than a star that comes away from a larger body’s gravitational field. These are more accurately defined as comets, asteroids or meteors. This occurs in our Solar System with so-called “shooting stars” being seen in the night sky. Space junk moves without much gravitational force acting on it, rather than orbiting around a large body like a planet. This allows for greater freedom to fly around the Solar System.
As Alpha Centauri gets closer, its gravitational influence continues to increase and send more junk into our space. This relationship is two-way, as our Solar System sends space junk into Alpha Centauri as well. The two systems should come closest to one another within the next 28,000 years, with greater gravitational pull exerted by both as this time window contracts. This is when we should expect to see more Alpha Centauri material in our Solar System.
Gregg says that space junk within our Solar System poses a greater danger to us than interstellar objects.
“Most interstellar objects pass through at high velocities and have low probabilities of impacting planets or spacecraft. Meanwhile, space debris in Earth orbit or near-Earth asteroids are far more relevant for near-term risks due to their abundance.”
At the moment, Weigert and Gregg do not foresee any danger to the planet. When space junk hits Earth, it rarely poses any harm or threat. The planet’s atmosphere usually reduces it to a smaller size by burning it up before impact. Most space junk that enters Earth’s atmosphere decreases to a size of no more than 100 micrometres. Scientists speculate that several trillion bits of space junk hit Earth each year, but make no mark on us due to its minuscule scale.
Moving forward, the researchers plan on using the same methods to look at larger star systems, including Beta Pictoris.